Floating NSPanel with rounded corners, showing sheet -> corners not masked

Hello all,

I am developing a swiftui macos app with a floating NSPanel with with rounded corners.

The app shows a few other NSPanels as sheet on the floating panel. (about, settings, etc).

This all works, with the exception that: when beginSheet is called, the parent window gets a standard overlay, to indicate that a modal sheet is shown. But this overlay is not respecting my rounded corner.

What could be wrong?

Check the image: Top part is my floating NSPanel with rounded corners

Bottom part is where beginSheet is called -> Notice the corners.

I have no idea where this overlay is rendered or how I can influence it to respect the rounded corners.

What could be wrong?

Thanks! Cheers

Gerd

Floating NSPanel with rounded corners, showing sheet -> corners not masked
 
 
Q